Key Findings

  • The main malaria vectors were An. gambiae in Cameroon, An. funestus s.l. and An. arabiensis in Kenya.

  • In Kenya, most of the primary vectors were cattle-fed and did not rely completely on human blood for their reproduction.

  • In Kenya, minor species are notably increasing and contributing to malaria transmission outdoors although at low levels.

  • The construction of a dam and increase in population in Nyabessan in Cameroon is likely to have influenced the increase in An. gambiae, while in Kenya, the climate and terrain likely influence the vector populations.

  • The number of mosquitoes collected, and the bite rate, was generally higher indoors than outdoors across all the sites.

  • Long-lasting insecticidal nets (LLINs) have had a positive impact on mosquito resting behaviour in Cameroon, as indicated by low mosquito densities collected using spray collections. However, many of the nets in this area were in poor condition. In Kenya, there was no mosquitoes collected using spray collection.

  • Resistance to pyrethroids was high among primary vector species. Other species showed variable susceptibility to insecticides between seasons.

  • Community members generally had a high awareness of malaria and preventive vector control measures across sites.